Carburetor combined with a feeding pump



Dec- 3, 1940 G. sTElNLEiN ETAL 2,223,971 CARBURETOR COMBINED WITH AFEEDING PUMP i Filed Feb. 17, 195s Inventors v Jew fw b/w lPatented Dec.3, i940 uNiTEo sTATEs- PATENT -orFicE- CARBURETOR COMBINED WITH AFEEDING PUIiIP Gustav Steinlein, Meinberg,` near Schweinfurt, and LudwigBruckmoser, Schweinfurt, Germany Application February 17, 1938, SerialNo. 191,007

In Germany February 19, 1937 y lil ib muniating with the interiorthereof, which pump ing outwards and at its free end provided with a isadapted to supply a. definite quantity of fuel push button, a spring 22disposed in the cylinder to the mixing chamber through an auxiliarytending to move the plunger upwards. When passage in order to vary theconstituent proporthe plunger is pressed down the said circumfertions ofthe mixture and to enrich the mixture ential groove thereof will becaused to regis- 20 for starting. ter with a bore 23 of the casingleading into the 20 The accompanying drawing, which formsa mixingchamber. part of this specification, by way of example The carburetorworks as follows: For the regillustrates an embodiment of the inventionand ular running the piston of the engine will draw shows in-y v in theairthrough the filter 9, passage `8 and Fig. l a vertical longitudinalsectional elemixing chamber l of the carburetor Where it 215.

vation through the mixing and the float chammixes with fuel injected bythe nozzle i0 into bers on the line A--B of Fig. 3; the chamber 1 andthen gets into the crank case. Fig. 2 a similar vertical section throughthe The sucking effect of the engine piston will also nozzle and thefloat chamber on the line C-D convey iuel from the float chamber throughthe of Fig. 3; A passages Ii and nozzle i0 into the chamber 1, 30

Fig. 3 a top planview of the carburetor with when the slide valve i3 isbeing raised. the air inlet passage shown in section; In order to obtaina mixture that will be richer Fig. 4 a vertical section through themixing for starting, the plunger rod 2i is pressed down chamber and thepump on the line E-F of Fig. sothat the plunger i8 at 'ilrst closes thebore 3, the throttle valve being omitted, and i6 through which the fuelhad been supplied from 35 l Fig. 5 a horizontal section through thefloat the floatchamber to the lower space of the chamber and the pumpcylinder on the line G-H pump cylinder. Thereupon the fuel retained inof Fig. 4. the cylinder i1 will be forced through the bores Likenumerals designate like parts throughout i9 and ISa and thecircumferential groove 20 all figures of the drawing. into the passage23 the orifice of which now 40 The carburetor comprises a. verticalmixing registers with the said groove 20; from here the chamber l, intowhich opens a horizontal air fuel flows to the mixing chamber 1. Theamount inlet passage 8 provided with a Wetair filter 9. of fuel suppliedin this way can be controlled Through the said passage 8 extends the,spray accurately as with each stroke of the plunger a nozzle i0 thebottom end of which is connected denite quantity only can be broughtinto the 5 to the interior of the float chamber I2 by bores mixingchamber. Ii of the body or casing of the carburetor. The After thedownward movement of the piston vertical mixing chamber 1 encloses areciprocal i8 has been completed, and the fuel contained in throttleslide valve i3 which is adapted to be the cylinder- I'ivbelow saidpiston has been inraised within the chamber 1 against the action ofjected through the passages i9, isa, 20 and 23 50 2 Claims.

The invention relates to carbureters and more particularly tocarburetors intended for feeding small internal combustion engines.

The object ofthe invention is to provide means f partly or completelyclosing the duct leading i from the spray nozzle and the air admissionaperture to the engine.

This object is attained by disposing at the side of the float chamber ahand operable pump coma spring 'la e. g. by means o f a Bowden wire il.The outlet end of the air passage 8 communicates with the mixing chamberl at the section of said chamber above the lowermost position of theslide valve i3 shown in Fig. 1, so that in this lowermost position, saidvalve closes the mixing chamber against the entrance of the air, so thatwhen the carburetor overflows, no fuel can get into the slide valvepassage. 'I'he spray nozzle l0 serves both as the main nozzle and as ai' pilot jet.

By the side of the float chamber there is in an inclined positiondisposed a pump cylinder i1 communicating with the interior thereof by abore i6. The plunger i8 of the pump contains l0 axial and radial boresi9,` I 9a beginning at the lower end of thesaid plunger and ending intoa circumferential groove or recess 20 of the same. The top of theplunger carries a rod 2i projectinto the mixture passage 1, the pressureon nthe plunger is released` and the piston i8 moves upwardly rapidlyunder the action oi' the spring 22 to the upper limiting position. Thelarger section of said piston thus shuts off the passage 23 55 and thelower end of the piston uncovers the end of the passage I3. The initialportion o! the upward movement of the piston I8, while the passages IS,ISa, 20 and 23 are filled with fuel from the previous downward movementof the piston, is'suiilcently rapid that there is not time for theliquid in the passages to ilow back into the cylinder, and air cannotbedrawn through the passage 23 and into the cylinder Il from the mixturepassage 1. After the passage 23 has been closed and the passage i6uncovered, thel continued upward movement of the piston i3 under theactionV of the spring creates a vacuum in the lower portion of thecylinder i7, and the fuel enters through the passage I8 into thecylinder I1 from the oat chamber i2, so that the cylinder is againloaded for the next discharge stroke of the piston.

We claim:

l. In a carburetor for small internal combustion engines, and of thetype having a float chamber, an air inlet passage, a mixing chamber intowhlchthe said air inlet passage opens, a throttle valve for said mixingchamber, and a spray nozzle in the said air inlet passage discharginginto the mixing chamber,- and the lower end of which communicates withthe oat. chamber, means for supplying fuel to said mixing chamber forstarting while said throttle valve is .in its closed position, saidmeans including a cylinder having and operatingv to close said passageto the float sassari a passage connected to said oat chamber and apassage connected to said mixing chamber posterior to said throttlevalve, a manually operable plunger reciprocable in said cylinderindependently oi' said throttle valve, a spring located in 5 the lowerend of said cylinder and normally holding said plunger in its upperposition, said plunger being provided with a substantiallylongitudinally extending passageway normally open to said passage whichconnects said cylinder and. 10 iloat chamber to permit the illing of thespace in the cylinder below the plunger with fuel, and said plungernormally closing said passage connecting the cylinder and said mixingchamber,

chamber and open said passage to said mixing chamber when the plunger ispushed into said cylinder against the tension of said spring, to torce adeinite quantity of fuel out of said space below the plunger into themixing chamber each 20 time said plunger is forced down.

2. In a carburetor as claimed in claim 1, having the cylinder arrangedat the side of the float chamber in s position inclined to the axes ofthe float chamber and the mixing chamber, and the 25 plunger having arod projecting outwardly and provided with a push button at its freeend.

GUSTAV STEINLEIN. LUDWIG BRUCKMOSER.

